Highly Efficient Perovskite Solar Cells with Gradient Bilayer Electron Transport Materials
journal contributionposted on 21.05.2018, 00:00 by Xiu Gong, Qiang Sun, Shuangshuang Liu, Peizhe Liao, Yan Shen, Carole Grätzel, Shaik M. Zakeeruddin, Michael Grätzel, Mingkui Wang
Electron transport layers (ETLs) with suitable energy level alignment for facilitating charge carrier transport as well as electron extraction are essential for planar heterojunction perovskite solar cells (PSCs) to achieve high open-circuit voltage (VOC) and short-circuit current. Herein we systematically investigate band offset between ETL and perovskite absorber by tuning F doping level in SnO2 nanocrystal. We demonstrate that gradual substitution of F– into the SnO2 ETL can effectively reduce the band offset and result in a substantial increase in device VOC. Consequently, a power conversion efficiency of 20.2% with VOC of 1.13 V can be achieved under AM 1.5 G illumination for planar heterojunction PSCs using F-doped SnO2 bilayer ETL. Our finding provides a simple pathway to tailor ETL/perovskite band offset to increase built-in electric field of planar heterojunction PSCs for maximizing VOC and charge collection simultaneously.
Read the peer-reviewed publication
F doping levelpower conversion efficiencyperovskiteenergy level alignmentheterojunction PSCsSnO 2 ETLcharge carrier transportdevice V OCF-doped SnO 2 bilayer ETLGradient Bilayer Electron Transport Materials Electron transport layersSnO 2 nanocrystalAM 1.5 G illuminationV OCEfficient Perovskite Solar Cells